Stray Light (Flare)

Hierarchical Data Format (HDF5) Files

Background Testing Calculation Testing With Imatest Inputs Outputs


Current Documentation
View previous documentation
View legacy documentation
All documentation versions


Hierarchical Data Format (HDF) 5 is a file format to organize large amounts of data within a single file [1, 2]. The file is broken up into datasets (typed multidimensional arrays) and groups (containers that can hold other datasets or groups). Both datasets and attributes may contain attributes about the data. HDF5 data will typically use a .h5 extension.

HDF5 Usage within Imatest

HDF5 files store data as binary chunks of data. This enables the storage of images within the results file, unlike JSON or CSV outputs.

HDF5 outputs were introduced in Imatest 22.2 with the stray light analysis feature.

Interacting with HDF5 Files


The HDF Group offers HDF® View, a free (with an HDF Group account) HDF5 data viewer [3].

A screenshot of a free HDFView application. The stray light output structure can be navigated by using the pane on the left. Here, a stray light metric image, accessible from within the output structure, is opened for viewing.

I/O Libraries

The HDF Group provides libraries in a number of programming languages for interacting with HDF5 files [4].

User Guides

The HDF Group provides a number of examples of working with HDF5 data [5]. 


The HDF Group provides a number of examples of working with HDF5 data [6]. 




[3] HDF® View.

[4] Libraries and Tools Reference.

[5] HDF5 User Guides.

[6] HDF5 Examples.